Admixing aluminosilicate builders with other ingredients commonly used in detergent compositions offers several advantages over spray drying crutcher mixes containing aluminosilicates. First of all, higher product densities and reduced drying loads can be achieved by removing aluminosilicates from the crutcher and admixing them. Aluminosilicates also interact with carbonates and amorphous silicates typically present in the crutcher, resulting in poorer calcium ion exchange capacity and granules solubility, respectively.
Agglomerates or particles containing aluminosilicate builders are described in the art. For example, U.S. Pat. No. 4,528,276, Cambell et al, issued Jul. 9, 1985, discloses agglomerates formed by mixing hydrated alkali metal silicates with zeolites while adding heat and moisture.
U.S. Pat. No. 4,096,081, Phenicie et al, issued Jun. 20, 1978, discloses detergents containing particulate mixtures of aluminosilicate, salt, and agglomerating agent, including polymers containing ethylene oxide units. The particulates are preferably made by spray drying or spray cooling. The agglomerating agent represents about 0.3 to about 3 parts of the particulate composition.
U.S. Pat. No. 4,414,130, Cheng, issued Nov. 8, 1983, discloses zeolite (preferably amorphous) agglomerates made using a water-soluble binder. Example 8 discloses an agglomerate made by mixing 50 parts amorphous zeolite and 50 parts linear alkylbenzene sulfonate slurry (60% active). It is noted that when crystalline Zeolite A is used in place of amorphous zeolite, the products are "pasty and never become satisfactorily flowing".
European Patent Application 340,013, published Nov. 2, 1989, discloses granular detergents containing 17-35% surfactant, at least part of which is anionic, and 28-45% (anhydrous basis) zeolite. The composition is prepared by granulation and densification in a high speed mixer/granulator in the presence of a binder, preferably water. In Examples 11-12, a powder prepared by dry mixing linear alkylbenzene sulfonate, nonionic surfactant zeolite, and other ingredients is densified/granulated after adding on 1% water as a binder.
European Patent Application 364,881, published Apr. 25, 1990, discloses in Example 7 "free-flowing granulates" made by granulating 12% nonionic surfactant, 20% of a suspension (31% active) of alpha-sulfo-fatty acid methyl ester surfactant, and 68% zeolite.
European Patent Application 22,024, published Jan. 7, 1981, discloses agglomerates containing zeolite, linear alkylbenzene sulfonate and polyethylene glycol. The only example shows drying a suspension of these ingredients to produce particles, not agglomerates.
U.S. Pat. No. 4,664,839, Rieck, issued May 12, 1987, discloses crystalline layered silicate builders and detergent compositions containing them.
Despite disclosures in the art of aluminosilicate agglomerates, there is a continuing need for development of a process for making free flowing agglomerates containing aluminosilicate and/or layered silicate builders having good dispersibility in water.